Examples for 8th grade - page 3

  1. AVG of INT
    seq_moon What is the average of the integers from 7 throuht 15 inclusive?
  2. Beer
    piva After three 10° beers consumed in a short time there are 7.4 g of alcohol in 5 kg adult human blood. How much is it per mille?
  3. Coin and die
    die Flip a coin and then roll a six-sided die. How many possible combinations are there?
  4. Diofant 2
    1diofantos Is equation ? solvable on the set of integers Z?
  5. MO SK/CZ Z9–I–3
    ball_floating_water John had the ball that rolled into the pool and it swam in the water. Its highest point was 2 cm above the surface. Diameter of circle that marked the water level on the surface of the ball was 8 cm. Determine the diameter of John ball.
  6. Diagonal
    rectangle_diagonal Calculate the length of the diagonal of the rectangle ABCD with sides a = 7 cm, b = 6 cm.
  7. Chickens and rabbits
    pipky In the yard were chickens and rabbits. They had 44 heads and 124 legs. How many chickens and how many rabbits was in the yard?
  8. Saving
    cars Kevin save € 4620 to buy a car. Yet it lacks save 65% of the car price. How much is the car?
  9. Ladder
    rebrik_1 Ladder 5 m long is leaning against the wall. It foot is 0.9 m away from the wall. In which height ladder touch the wall?
  10. Number
    sqrt_2 Is number 4.764023 irrational?
  11. Tractors
    tractors Fields go plow two tractors with various performance. The first tractor plow whole field in 5 hours, the second tractor plow whole field 5 hours longer. How long take plow whole field with two tractors?
  12. Segments
    abs Which of the pairs of numbers on the number line encloses the longest segment: ?
  13. Mr Novak
    Salary-increase Mr Novak earns an average 638 euros. When increasing the salary they gave him a choice: ? What is better choice for Mr Novak?
  14. Drunk man
    drunk-man Drunkman has 2.1‰ of alcohol in the blood. How many grams of alcohol has in blood, if he have 6 kg of blood?
  15. Seedcake
    pletenky Seedcake costs 50 cents. How many minimum seedcakes we must buy that we can pay in cash only whole euros?
  16. Density - simple example
    mercury Material of density of 1278 kg/m3 occupies a container volume of 80 cm3. What is its mass?
  17. Road repair
    workers_1 Road repair took 16 days for 34 workers if they worked 6 hours a day. How many days take repair same road 33 workers if they work 6 per day?
  18. Time
    time Write time in minutes rounded to one decimal place: 1 h 42 m 22 s.
  19. Railways
    railways Railways climb 5.8 ‰. Calculate the height difference between two points on the railway distant 2389 meters.
  20. Vinegar 2
    ocet How many percentage of getvinegar solution, if we mix to 14.5 liters of 7.8% and 2.5 liters of 5.8% vinegar?

Do you have interesting mathematical example that you can't solve it? Enter it and we can try to solve it.



To this e-mail address we will reply solution; solved examples are also published here. Please enter e-mail correctly and check whether you don't have a full mailbox.